We examined the effects of a single or 2.5-fold dose of dephereline [a gonadotropin-releasing hormone (GnRH) analogue] as well as the drainage of the smaller follicle at the time of insemination on ovulation in dairy cows with two follicles of pre-ovulatory size in the same ovary. The three study groups included 220 monovular cows (control), 110 non-drained cows with two follicles, and 110 cows with two follicles, of which one was drained. In each group, cows treated with a single dose or 2.5-fold dose of dephereline showed similar results following treatment. Ovulation failure of the non-drained follicle occurred in 29.1% of the drained cows, whereas ovulation occurred in 96% of the non-drained and control cows. Twin pregnancy was recorded in 19.4% of the pregnant non-drained cows with two follicles. In conclusion, the increased dephereline dose did not improve the ovulation rate in any group. Follicular drainage, however, prevented twin pregnancy in cows with two follicles, but also resulted in an increase in the non-drained follicle’s rate of ovulation failure.

中文翻译：

---

双胎妊娠预防策略（如 GnRH 剂量和较小卵泡引流）对同一卵巢内有两个排卵前大小卵泡的奶牛排卵的影响

我们检查了单剂量或 2.5 倍剂量的 dephereline [促性腺激素释放激素 (GnRH) 类似物] 以及授精时较小卵泡的引流对具有两个卵泡的奶牛排卵的影响。同一个卵巢的排卵大小。三个研究组包括 220 头单胎母牛（对照）、110 头具有两个卵泡的非引流母牛和 110 头具有两个卵泡的母牛，其中一只母牛已经引流。在每组中，用单剂量或 2.5 倍剂量 dephereline 治疗的奶牛在治疗后表现出相似的结果。29.1% 的排卵母牛出现未排卵卵泡排卵失败，而 96% 的未排卵和对照母牛排卵。19.4% 的有两个卵泡的未引流妊娠母牛记录到双胎妊娠。总之，在任何组中，增加 dephereline 剂量都没有提高排卵率。然而，卵泡引流阻止了具有两个卵泡的奶牛的双胎妊娠，但也导致未引流卵泡的排卵失败率增加。